Here I found an interesting blurb on the differences between what Latino, Hispanic and Spanish means:

Hispanic
Probably the most common term in the Northwest, the word Hispanic has an extremely broad definition. It can be used to refer to anyone who is from Mexico, Central America, South America, Puerto Rico or Cuba - or their descendants, even if they were born and raised in the United States.
It can be used interchangeably with Latino, but it can have a slightly different connotation. There are some who object to its emphasis on the word Spain, or its sterile origin as a term created by the U.S. government as a census category.

Latino/Latina
Maybe the best choice when referring to an entire population rather than an individual person, the term Latino can be used to refer to anyone of Latin American descent.

Depending on the part of the country, it can be used instead of Hispanic. It's more likely for people within the Latino community to use this term in favor of Hispanic, especially in California.

Chicano/Chicana
A politically loaded and sometimes derogatory term, Chicano traces its roots to the student movement of the 1960s.

Technically, it refers to someone of Mexican descent who was born and raised in the United States, but it usually also is associated with activists and the political left.

It was created by students who believed neither the terms Mexican nor American, or even Mexican-American, were adequate to describe who they were.
"The power of that decision is more significant than the actual term," Pizzaro said. It is sometimes used as an insult within the Mexican culture to refer to someone who is no longer a true Mexican.

Mexican-American
An American citizen of Mexican heritage.

Mexican
Technically a Mexican citizen, it is used sometimes by mistake to refer to a Mexican-American. Just because someone lives in the United States doesn't mean he isn't a Mexican citizen.

Spanish
Either the language spoken in Mexico and throughout South America, or a person from Spain. It should not be used to refer to someone from Mexico or South America, although white Americans sometimes make this egregious blunder.

Anglo
A non-Hispanic white person, according to the dictionary. The term is used mostly by Hispanics to refer to Caucasians, although whites are beginning to use it increasingly to refer to themselves, as well.

Although the term 'white' is often used as a synonym for Caucasian, it is not. Hispanics can be any race or color, including white.
It's true that many of the Hispanics in Eastern Washington are dark complected, but there are white Hispanics with blue eyes and blond hair.